High Efficient Video Coding (HEVC) is a new generation of video coding standard developed as a successor to H.264. In HEVC, each image frame is applicable to an intra-frame prediction mode, and there are 35 intra-frame prediction modes available.
To select an intra-frame chromaticity prediction mode for a current image frame, firstly, 5 of the 35 intra-frame prediction modes are required to be selected as candidate intra-frame prediction modes, then a coding cost value, which can be represented by a code rate resulting from a coding processing and a distortion rate of reconstructed image frames, is calculated for each candidate intra-frame prediction mode, and last, the optimal one of the five candidate intra-frame prediction modes is selected according to the calculated coding cost values as the intra-frame chromaticity prediction mode of the current image frame.
In the process of implementing the disclosure, the inventor has found that the foregoing technology has the following technical problems: as a large amount of calculation needs to be conducted for calculation of a coding cost value and it is required to calculate the coding cost value for each candidate intra-frame prediction mode during the process of selecting an intra-frame prediction mode for the current image frame, low calculation efficiency is resulted.